Attracting magnetic BDD particles onto Ti/RuO2-IrO2 by using a magnet: A novel 2.5-dimensional electrode for electrochemical oxidation wastewater treatment

• Published in: Chinese chemical letters 2024-11, p.110641, Article 110641
• Main Authors: Shao, Dan, Lyu, Yujing, Liu, Chengyuan, Wang, Hao, Ma, Ning, Xu, Hao, Yan, Wei, Jia, Xiaohua, Song, Haojie
• Format: Article
• Language: English
• Subjects: Boron-doped diamond; Hybrid electrode; Multi-physics simulation; Organic wastewater; Real wastewater
• ISSN: 1001-8417
• DOI: 10.1016/j.cclet.2024.110641

Boron-doped diamond (BDD) is a well-known anode material with a high pollutant degradation ability for electrochemical oxidation wastewater treatment. Nevertheless, the cost of production and mechanical strength of BDD membranes remain unsatisfactory. Magnetic BDD particles derived from industrial waste may represent a promising alternative to BDD membranes, although the challenge remains in assembling these particles into a usable electrode. In this study, magnetic BDD particles were attracted to a Ti/RuO2-IrO2 electrode using a magnet, thus constituting a novel 2.5-dimensional (2.5D) electrode. To ascertain the structure-activity relationship of the novel electrode, essential characterizations, multi-physics simulations, pollutant degradation and electrosynthesis experiments were conducted. The results indicate that an appropriate quantity of BDD particles (0.1 g/cm2) can enhance the number of active sites by approximately 20%. A strong synergistic effect was observed between the Ti/RuO2-IrO2 and BDD particles in the degradation of various pollutants, including azo dye, p-benzoquinone, succinic acid and four kinds of real wastewaters, as well as glycerol conversion. The joint active sites on the interface between Ti/RuO2-IrO2 and BDD particles, as well as the inner active sites on BDD particles, have been identified as crucial in the mineralization of pollutants and the generation of value-added products. The optimal amount of BDD particles (0.1 g/cm2) is sufficient to preserve the joint active sites and to maintain an adequate polarization on the BDD particles. Nevertheless, the hybrid feature of the 2.5D electrode is diminished when a greater quantity of BDD particles (0.3 g/cm2) is loaded. Magnetic BDD particles abraded during cutting on the diamond wire are magnetically attracted to the 2D Ti/RuO2-IrO2 to form 2.5D electrodes. The strong synergistic effect between the Ti/RuO2-IrO2 and BDD particles in the degradation of various pollutants, including azo dye, p-benzoquinone, succinic acid and four kinds of real wastewaters, as well as glycerol conversion, which is dependent on the joint active sites on the contact interface and the inner active sites on the BDD particles. [Display omitted]